The puzzle of pilot whales

They strand on our shores in greater numbers than any other species of whale. Scientists believe they know why, but there is much about these animals that remains an enigma, and the strandings continue to happen.

Every year, their tragedy plays out on our shores. We see news footage of their sleek, coal-black bodies rolled and tumbled by the surf and strewn along sandy beaches like driftwood logs. We hear the piercing, plaintive whistles of their distress. In dozens, in hundreds, they lie bereft in helpless disarray.

People kneel beside them, propping them up, covering them with towels and bed sheets, pouring buckets of water on their lacquered skin. Some rest a hand on their slick flanks, say words of encouragement and solace. Marine mammal rescue experts in fluoro vests marshal the dozens of volunteers who have come to the beach to help. They manoeuvre the living animals on to inflatable pontoons and push them back out to sea. The dead are left for burial in the dunes.

We ask why. What kind of animal are these, which we rarely see except when they come to grief—increasingly a shared grief, theirs and ours. If we are so disposed, we might ask who these creatures are—warm-blooded like us, possessing brains of deep complexity and wondrous size. Who are these ocean minds?

Hundreds of volunteers, along with marine mammal specialists from the Department of Conservation, Project Jonah, Orca Research Trust, Far North Whale Rescue and local iwi Ngati Kuri, hurried to Spirits Bay to attempt a daring rescue. The first step was to manoeuvre the surviving whales (weighing between one and two tonnes) onto tarpaulins so they could be shifted by earthmover to a tidal inlet where they could rest for the night.

They have been called blackfish, the howling whale, the bottle-head whale, but we know them as the pilot whale. They get that name from a misconception: that there is a leader, a cetacean navigator who pilots the group, even unto death. That’s not the case, but the name has stuck.

We say “pilot whale”, but, like the mako shark (or New Zealand’s freshwater eels, for that matter), they come in two types based on fin length. By far the more commonly seen species in cool temperate waters like ours is the long-finned pilot whale, Globicephala melas, which means “black with a bulbous head”. The short-finned pilot whale, which lives in warmer waters, fares even worse etymologically. Globicephala macrorhynchus means “bulbous head with a big snout”.

That cephalic swelling, so noticeable in pilot whales, is called the melon. It is a tissue mass of wax and fat that functions like the lens of an eye, only for sound, focusing and modulating the whale’s calls and clicks. All toothed cetaceans have this bulb. These animals live in a world drenched with sound. Sound is the basis of their navigation, their feeding, their communication, and some would say their culture. They use short-range echolocation clicks to hunt in total darkness, like bats, and long-range lower-frequency sound to interact with each other and with the ocean realm.

Baleen whales, the other great family of cetaceans, do not have an equivalent of the melon. They have no need to echolocate their prey. Jaws agape, they gulp vast shoals of krill and fish like living seine nets. But for them, too, the oceans are a boundless auditorium that they fill with voice and song.

Baleen whales rarely mass-strand. It is the toothed whales that beach themselves in large numbers, and New Zealand has one of the highest rates of herd stranding in the world. Almost half of the world’s 89 species of cetacean have stranded on our shores. The commonest species to strand is the pygmy sperm whale—though it is mostly individuals that strand. For mass strandings, however, no species comes close to the long-finned pilot whale. The largest stranding event ever recorded in New Zealand—perhaps in the world—took place in 1918. Though details are scant, an estimated 1000 pilot whales came ashore at Long Beach, on the western side of Chatham Island.

Through the night, volunteers kept watch in freezing temperatures, trying to calm the whales with their words and presence. Many volunteers built close emotional bonds with their charges, giving each a name—often those of loved family members. In the morning, the whales were loaded onto six trucks packed with sand and hay, then driven 50 kilometres south on winding, sometimes unsealed roads to sheltered Rarawa Beach. Here sea conditions were calmer, and a refloat could be attempted.

Between 1976 and 2000, 165 pilot whale stranding events were recorded in New Zealand, though only half of these were herd strandings; the other half involved single individuals. In all, 6000 whales stranded, and a third of these were successfully refloated. (See sidebar ‘Coming to grief’).

Why whales strand is an enigma that has perplexed people since ancient times. “It is not known for what reason they run themselves aground on dry land,” observed Aristotle 2500 years ago. “At all events, it is said they do so at times, and for no obvious reason.”

More than a dozen theories have been advanced, from the technical (geomagnetic anomalies) to the psychological (a subconscious longing for land). In 1991, Mark Brabyn, a marine mammal researcher with the Department of Conservation, compiled and analysed all New Zealand whale stranding records, looking for patterns and seeking a cause.

Death traps

One of the patterns Brabyn found is that live strandings are clustered at certain “stranding hotspots”, while the beaching of individual dead animals occurs uniformly around the coastline (reflecting the widespread distribution of whales in New Zealand waters). This fact alone allowed Brabyn to reject several theories. For instance, if there were a land-seeking drive in cetaceans—a genetic memory based on the fact that the ancestors of whales and dolphins lived on land some 40 million years ago, before returning to the sea—then animals following this impulse would be expected to beach themselves without regard to location.

Similarly, if herd strandings are triggered by a “key whale”—a cetacean rangatira whose distress through getting into difficulties in shallow water induces the tribe to mass-strand in solidarity—then these occurrences should be widespread, argued Brabyn. In reality, they occur repeatedly in the same spots.

Could such locations be the cetacean equivalent of elephant graveyards? The legendary Jacques Cousteau thought it was possible that elderly whales, “sensing that death was near, summoned their last ounce of strength to cross thousands of miles and breathe their last on ancestral burial grounds”. But Brabyn argues that the whale-graveyard hypothesis cannot explain why young, healthy whales strand in large numbers, and not just ailing elders.

Rescuers used earthmovers at Rarawa Beach to lift the whales from trucks into the water, before their release back into the wild. Of the 24 pilot whales transported from Spirits Bay, 21 were successfully refloated, of which seven re-beached and had to be euthanised. Only 14 made it back to sea.

Brabyn also eliminated harassment by predators (such as orcas) and illness caused by parasites or disease as inconsistent with the clustered occurrence of herd stranding. “Sick whales should strand anywhere,” he noted.

Could whales be stranding because of navigational malfunctions based on anomalies in the Earth’s magnetic field? That theory was put forward by a British researcher who found that all of the 70 live strandings in the British stranding record occurred where geomagnetic anomaly contour lines ran perpendicular to the coast. However, no such relationship has been found in New Zealand. “Where the geomagnetic contour lines ran perpendicular to the coast, the number of strandings was similar to that occurring where the contour lines ran parallel to the coast,” noted Brabyn. “Whales seem oblivious to direction of geomagnetic contour lines.”

What emerges as the strongest factor in herd stranding is perhaps the most intuitive: that long, gently sloping beaches are natural “whale traps”.

The idea is that offshore species, unfamiliar with this kind of topo-graphy and its associated tides and currents, find themselves getting shallower and shallower, until it’s too late to retreat.

This explanation fits with data that show that it is offshore species that strand the most. Inshore cetaceans, such as coastal dolphins, are presumably knowledgeable about coastlines and the dangers they present, and rarely live-strand. (Hector’s dolphins, for instance, never strand as herds the way pilot whales do.)

Sonar fail

But why should a gently sloping beach be such a deadly snare for pilot whales? These animals are, after all, experts in echolocation. Could they not readily detect the danger and beat a retreat to deeper water?

Researchers in Western Australia have offered a bioacoustics explanation of why toothed whales’ echolocation capabilities might let them down. They focused their study on Geographe Bay, near the south-western tip of Australia, where several mass strandings have occurred, including 320 long-finned pilot whales in 1996 and 120 false killer whales in 2005.

Along this broad crescent of coastline the slope of the beach is rarely more than half a degree, and often much less. Two metres of fall in a kilometre of distance from shore is not uncommon. The researchers argued that in such gently sloping bays an echolocation click projected towards the shore attenuates through multiple reflections to a point where it is not detectable to the animal that produced it. In essence, the whales send out a sonar “ping” but don’t get an echo—and this may suggest to them that there is no obstacle ahead.

“The reflections contain important information about the location of the shoreline,” the researchers write. “Successful detection of a shoreline from reflections may only occur at a point where the cetacean is at a high risk of stranding or has already stranded.”

Failure to detect the proximity of the shore—or detecting it too late—could result in confusion and disorientation and in navigational errors that trigger the stranding of the entire herd.

[sidebar-1]

Compounding the problem of a super-low-angle shoreline, say the researchers, is the presence of microbubbles in the water—relatively long-lived tiny bubbles produced by rainfall, storm turbulence and even the respiration of marine algae. These could contribute further to the whales’ loss of navigational perception. They would be operating in an acoustical fog.

Many of the beaches where pilot whales strand regularly in New Zealand share similar topographical properties to those of Geographe Bay—Farewell Spit being one example. In addition, several common stranding beaches are bounded by protruding spits of land, which may add to the whales’ navigational challenge in finding a way back out to sea. A further contributing factor is that in such locations the tide often goes out rapidly. If the herd is already milling about in some confusion or uncertainty they might simply get stuck.

Suicide or altruism?

Physiological factors alone seem inadequate to explain some aspects of stranding, such as the fact that refloated whales, even when guided away from a death-trap beach, often show great determination to beach themselves again.

Observing this apparent death-wish has led some researchers to suggest that stranding is cetacean suicide, and that just as certain locations are hotspots for humans who decide to take their own lives (bridges, for instance), gently sloping sandy shores are “suicide beaches” for whales. Yet the suicide theory tends to fall apart when you consider the large number of whales that are successfully refloated. The rescue rate in New Zealand is now between half and three-quarters of all individuals that strand. From the few overseas studies that have tracked refloated pilot whales by satellite, these animals successfully rejoin herds and appear to resume their normal lives.

Rather than suicide, it is more likely that the bonds of social cohesion cause refloated whales to return to shore if others of their group remain in distress. It is for this reason that refloating stranded whales is now carefully managed to ensure animals leave the beach together, or in large enough groups to offset the impulse to return.

Some researchers believe that social cohesiveness is a key reason for the evolutionary success of cetaceans. It may have developed as a response to predators, suggests Brabyn. “Living in cohesive schools and developing supporting behaviour (social whales actively support sick members of their herd) enabled whales to overcome predatory pressures,” he notes.

Long-finned pilot whales are an integral part of New Zealand’s coastal waters, but in the North Island they tend to be seen 10 kilometres or more offshore where water temperatures are around 20ºC. They feed at night, and during the day they rest, travelling slowly and socialising in pods of about 30 individuals. Many pods may travel in close proximity, forming loosely connected “super-pods” of up to 1000 animals.Pods of up to 1000 offshore bottlenose dolphins have been seen travelling with pilot whales, but the reasons for the association are unclear. There could be a feeding benefit for pilot whales, since bottlenose dolphins are highly efficient at rounding up schools of fish. On the other hand, dolphins may be gaining some measure of protection from predators by staying close to the much larger pilot whales.

These social bonds may even transcend species boundaries. In 2008, it was widely reported that a mother and calf pygmy sperm whale, which had stranded and been refloated at Mahia Beach, south of Gisborne, but seemed unable to find their way to deeper water, were rescued by a resident bottlenose dolphin. The dolphin, which locals had named Moko, appeared to lead the two disoriented whales past a sandbar and into a channel that took them safely out to sea.

Earlier this year, it was reported that humpback whales tried to prevent a pod of orcas from eating a gray whale calf that the orcas had just killed off Monterey in California. An earlier incident from Antarctica was cited in which a Weddell seal, fleeing from an orca attack, was carried protectively on the chest of an upside-down humpback whale until it could scramble to safety on to an ice floe.

Such behaviours have been interpreted as instances of interspecies altruism. Whether they are or not, evidence of social interactions within and between cetacean species continues to accrue. For offshore species such as pilot whales, gathering behavioural data is costly and demanding, but from what little is known about these animals, they appear to have an intricate and long-term social structure in which mothers are dominant. Herds can be up to 1000 strong, but these “super pods” seem to be temporary associations of smaller extended family units of a few dozen individuals. It may be that the smaller kin groups join up for feeding or breeding opportunities, or for enhanced security from predators—the same safety-in-numbers benefit that fish gain from schooling. Both male and female offspring remain with their mother, even after reaching sexual maturity (which for females is around eight years of age, and for males 12).

Older, post-reproductive females also remain with the group, and may play the role of nannies. Given that mothers nurse their offspring for three years or more, but need to make deep feeding dives that are beyond the range of their calves, having extra care-givers on hand could be vital. Female pilot whales may live into their 60s, while the life-span of males averages 35 to 45. Perhaps, as is the case with their land-based equivalents—elephants—older matriarchs are the holders of cultural memory, retaining knowledge of foraging areas and migration pathways and passing this on to the young.

Kinship breakdown

The same matrilineal group structure seen in pilot whales is found in other cetaceans, including sperm whales, false and pygmy killer whales, melon-headed whales and rough-toothed dolphins—all species that are known for mass stranding.

Because of the association between social cohesion and stranding, Noumea-based marine mammal biologist Marc Oremus and three colleagues decided to analyse the DNA of 1033 whales from 12 pilot-whale stranding events in New Zealand and Tasmania between 1992 and 2006 to determine their kinship connections.

They were able to conduct this research because small samples of skin from the stranded whales had been collected by scientists and preserved in the New Zealand Cetacean Tissue Archive at the University of Auckland. This archive, one of the largest of its kind in the world, covering 36 species, is yielding important insights into the life histories of many poorly known cetaceans. (See sidebar ‘The library of flesh’).

The pilot-whale results were surprising. The stranded animals were more genetically diverse than expected, implying that matrilineal units were mixing freely within larger herds. Finding multiple “matrilines” within a single stranding “challenges the hypothesis that mass strandings are driven primarily by kinship-based behaviour”, the researchers say. If group cohesion is not based on kinship, it may have come about through reciprocal altruism—a term evolutionary biologists use to describe “you scratch my back, I’ll scratch yours” arrangements between organisms.

In addition to their findings on genetic diversity, the researchers discovered a curious anomaly: mothers and their unweaned calves did not strand in close proximity to each other, and in some cases the mothers of calves were not among the stranded whales at all. Oremus and his colleagues speculate that disruption of kinship bonds could be a contributing factor in stranding. Some kind of social breakdown through competition or aggression may lead to confusion, loss of navigational certainty and the eventual beaching of the herd.

Whale researcher Jochen Zaeschmar, aboard his ketch Manawanui, scans the sea for whales east of the Poor Knights Islands, in Northland. He started out working on false killer whales, but these animals often associate with pilot whales, and reported sightings from the public often confused the two species, so Zaeschmar is now building a photo-ID database of both. He and his colleagues are developing an application so that boaties can upload photographs of pilot and false killer whales to a website directly from their smartphones. Time and location data, automatically embedded in the pictures, will allow researchers to build up a picture of the animals’ movements.

This finding has implications for managing whale rescues. Rescuers have often inferred that a calf’s mother will be nearby on the beach, and when refloating occurs, the calf and adjacent adult females are kept together. If mothers strand at some distance from their offspring, that protocol makes less sense.

Research like that of Oremus and his colleagues tends to underscore how little we know about what is really going on in the ocean. No one is even sure what draws pilot whales to inshore waters in the first place. Are they coming close for food? It could be that they follow their target prey—squid and octopus, with occasional mackerel, herring, cod, turbot, hake and dogfish—into continental-shelf waters. The fact that pilot whales have been caught in jack mackerel trawls off the west coast of the North Island gives slight support to this possibility.

Perhaps the animals’ prey preference changes with the seasons or with their breeding cycle. But often the stomachs of stranded pilot whales are found to be empty, so other factors may be involved in the movement of herds from offshore to inshore—from the safety of distant seas to the dangers of the coastline.

There certainly seems to be a seasonal component to that movement, with animals coming closer to the coast in summer and moving away in winter. But inshore movement doesn’t necessarily correlate with frequency of stranding. In Northland, most strandings are in winter, perhaps associated with the season’s strong, persistent onshore winds that compound wave turbulence and environmental noise into a cacophony of echolocation problems.

In Golden Bay, on the other hand, most pilot-whale strandings occur in summer, between October and January, with January the peak month, perhaps pointing to an entirely different mechanism at work there.

[Chapter Break]

If warm currents are bringing pilot whales close to shore in summer, where the animals travel during the rest of the year remains anyone’s guess. There has been no satellite tracking of pilot whales in New Zealand, and because their usual habitat is many kilometres offshore, finding them by boat is needle-in-a-haystack difficult.

Or so it was thought, until Jochen Zaeschmar, a graduate student at Massey University’s Coastal-Marine Research Group, took up the challenge and began to look. Zaeschmar was well positioned for the task: he operates a yacht-based ecotourism business in the Bay of Islands, a popular gamefishing destination where charter launches regularly travel 10 to 20 kilometres offshore in search of marlin and other trophy fish. Zaeschmar and his colleagues set up a tollfree number so that gamefishing skippers could report sightings of pilot and false killer whales (0800 FAR OUT), and the calls started coming in. As the calls came in, the researchers went out to investigate.

“The first surprise was that pilot whales are a lot more common than most people think,” Zaeschmar told me when I visited him on his steel-hulled ketch at Opua. “They’re not random strangers, coming only occasionally into the 12-mile zone. They’re here all the time, and the more time you spend out there, the more pilot whales you see.”

In part, Zaeschmar’s work on pilot whales arose because game-boat skippers and other boat operators kept misidentifying the species he was actually trying to study: false killer whales. The two species are easily confused, and Zaeschmar ended up with more pilot-whale data than false-killer-whale data as a result. So it made sense to broaden the research to include both.

Pilot whales’ bulbous foreheads are due to a mass of underlying tissue called the melon, which focuses and modulates the animals’ vocalisations. All toothed whales have this tissue. They hunt by echolocation and maintain close-knit extended family units for which aural communication is essential.

False killer whales (also known by their genus name, Pseudorca) are much rarer than pilot whales, and they form long-term resident groups in New Zealand waters. After several years of observing and photographing them, Zaeschmar says he “knows them all now”.

“With pilot whales it’s the opposite,” he says. “Every time you see them, it’s a new group.”

There are occasional repeat sightings within a season, but, unlike the situation with false killer whales, it’s rare to see the same individuals from year to year.

“The standard social unit seems to be between 30 and 50 animals, but groups are constantly coming together then splitting apart again,” says Zaeschmar. “At sea, it’s not unusual for us to see 200 to 300 whales at a time. You wonder, ‘Are they together, or what?’”

These large groups aren’t always a picture of cetacean harmony. On several occasions, Zaeschmar has witnessed animals tail-slapping, jostling and head-butting each other. “You sometimes see blood,” he says. It’s usually males that are showing aggression, and it’s probably related to mating, he thinks. An overseas study has shown that male pilot whales are much more likely than females to have broken jaws. They may be using the melon as a battering ram to beat rivals into submission.

A further twist in the population dynamics of pilot whales is that some groups may be more migratory than others. “In the northern hemisphere, researchers have found that some pilot whales are nomads, while others are locals,” says Zaeschmar. “Maybe the same thing happens here.” It could be that the nomadic groups, lacking the familiarity with coastal conditions that the locals possess, are more likely to strand. That’s something Zaeschmar hopes future research will shed light on.

“As always, more questions than answers,” he says.

[Chapter Break]

On a boat out of sight of land, it can be easy to think that all is well in whales’ oceanic universe. But increasingly the human world encroaches on the cetacean world. We assist them back into the sea when they strand, going to Herculean lengths to do so, but sanction the industrial-scale removal of their food by fishing trawlers and the sonic disruption of their habitat by military sonar, seismic surveying and ubiquitous propeller and engine noise—not to mention the human-induced global warming that is increasing the acidity and temperature of the seas they swim in.

Warming seas are already having an impact on pilot-whale populations in the northern hemisphere. Short-finned pilot whales—the warmth-loving member of the two pilot-whale species—appear to be moving into waters used by their long-finned relatives, and producing hybrid offspring with them. If the trend continues, the two species—which diverged more than half a million years ago—might eventually become one.

A more immediate concern is the impact of human noise on the animals’ wellbeing. There have been multiple international reports of military sonar causing the deaths of whales and dolphins. Necropsies of affected animals have shown haemorrhaging around the ears and gas-bubble lesions in internal organs, possibly the result of decompression during sudden ascents triggered by sonar disturbance.

[sidebar-2]

At the less-traumatic end of the response spectrum, loud sounds or sudden changes in sound could be causing confusion and disorientation in whales and dolphins. University of Auckland whale ecologist Rochelle Constantine says that just as human hearing can be compromised by loud noise, temporary or permanent loss of hearing in whales can result from exposure to disruptive sounds under water.

“There are a lot of areas in the ocean where not just sudden blast trauma occurs—the kind that does physiological damage to the ears—but also less-deafening sounds that are still loud enough to cause chronic stress, disrupt group cohesiveness and force the animals to move away,” she says.

If marine mammals are having to leave feeding and breeding areas they have used for generations in order to avoid intrusive underwater sounds, the conservation implications could be severe.

A final touch as a refloated pilot whale makes its way back out to sea. Volunteers who help rescue whales find it a moving experience, as whales’ lives seem so parallel to our own.

The wider issue is that with so much noise in the sea now, whales may not be able to communicate so effectively. It would be like trying to have an intimate conversation at a noisy party. That could be a minor inconvenience, or a potentially life-threatening environmental change. We just don’t know.

What we do know is that just as our flightless birds, giant insects, ancient reptiles, alpine plants and Gondwanan beech forests are a unique and irreplaceable treasure that New Zealanders are called on to protect, so, too, do we have responsibilities towards the whales and dolphins that dwell in our seas. They come here in such numbers and in such diversity because our marine environment is a nexus of warm currents, cool upwellings, deep canyons, tall seamounts—a veritable melting pot of oceanographic features, all of which attract cetaceans and their prey. And our islands happen to lie in a direct line between Antarctica and the islands of the South Pacific—an ancient migration path of the great whales.

Whales returned to the sea 40 million years ago. We marvel at the consciousness they have developed. Perhaps the sea is inviting us to return, in our consciousness, to the place where life began—returning as guests and guardians, rather than as dominating masters. Returning not because it has something we want, but because it is something we need. Watch the tears in the eyes of volunteers at a whale stranding, or the rapture on the faces of guests on a
dolphin-watching cruise, and you will see a connection being made. Our seas and our selves—a mystery, a wonder, and a tie that binds.

The library of flesh

A 25-year tissue archive is a scientific goldmine.

Can any good come from a whale stranding? From live strandings, certainly—many animals are rescued, and the volunteers who assist at a stranding derive emotional and spiritual satisfaction from coming to the aid of fellow sentient beings.

But the majority of cetacean strandings are of single animals, often dead or dying. Is there an upside to those events? In terms of scientific dividend, the answer is yes. Over the past 25 years, small samples of skin and blubber from whales, dolphins and porpoises that have washed up on New Zealand shores have been collected and stored in ethanol at minus 20ºC. A total of 2600 specimens from 36 cetacean species now reside in five freezers in the biosciences building at the University of Auckland. It is one of the largest such collections in the world.

When sampling began, biochemical techniques for analysing the specimens were limited. Now, with rapid advances in DNA-sequencing techniques, the cetacean tissue archive is proving to be a goldmine of information about the population structure, life history and movement patterns of rare species. It is providing a window on an otherwise invisible world.

The keeper of the archive is whale biologist Rochelle Constantine. I met her in late July at the biosciences building—my old stamping ground when I was a marine zoology student. As we walked to a park bench to enjoy the weak sunshine of a winter’s day, I remarked on the leaves of the ginkgo trees that had made a golden carpet on the lawns and paths. Constantine asked if I knew that there is a whale called the ginkgo-toothed beaked whale. I did not, but was enchanted to think that a whale shares its name with this most graceful and ancient tree. (Later, Constantine sent me a photograph of the teeth—they are indeed the spitting image of ginkgo leaves.)

The tissue archive has been a revelation into the lives of the beaked whales, the Ziphiidae, 22 enigmatic deep-ocean species that are rarely, if ever, seen at sea. Thirteen of these species have stranded in New Zealand—the highest stranding incidence of beaked whales in the world. There was excitement among cetologists in 2012 when a tissue sample from the archive was used to confirm the world’s first-ever sighting of a spade-toothed beaked whale. A mother and calf of the species had stranded and died on Opape Beach, near Opotiki.

Prior to that stranding, the species was known only from a jaw found on the Chatham Islands, a skull from White Island in the Bay of Plenty, and another skull from Robinson Crusoe Island, 670 kilometres off the coast of Chile—three bones collected over a 100-year period.

The archive’s real power, though, is in the insights it allows into the population structure of unseen whales—information hard-wired into their DNA. In 2015, Constantine’s master’s student Kirsten Thompson analysed tissue samples from 94 Gray’s beaked whales which had stranded on New Zealand and Australian shores over a 22-year period. She and her colleagues had expected to find genetic differences between the New Zealand and Australian animals, but, surprisingly, they found none. It seems this species of beaked whale ranges freely across a wide swath of ocean, and has not suffered the population bottlenecks found in species with more restricted distributions.

Such results are important for global conservation of beaked whales, because they are known to be highly vulnerable to noise produced by human activities in the ocean, and have suffered sharp population declines in some parts of the world as a consequence.

One-third of the tissue archive’s samples are from pilot whales—a library of flesh that only increases in value as the years pass. Who knows what questions these innocuous cubes may help to answer in future, in the changing ocean world.

Coming to grief

Public reaction to whale strandings in New Zealand has changed radically in the past century and a half.

In pre-European times, a stranded whale was welcomed as a gift from the gods. For some hapū, whalebone was more highly prized than pounamu. Whale oil had a number of uses—such as for lighting, food storage and timber preservation—while the unexpected arrival of several tonnes of protein on your doorstep could be cause for major feasting.

For early Pākehā settlers, a beached whale was also a windfall—a stranded asset, so to speak. In 1910, two herds of pilot whales of about two dozen each beached at Collingwood and Pakawau in Golden Bay. “All the fish have been secured,” reported the Nelson Evening Mail, “and are being turned into money by local fishermen and others, who expect to make about £3 a fish.”

A few years later, when a school of 37 pilot whales came ashore on Orewa beach, just north of Auckland, local residents immediately set about chopping their marks into the animals with spades, preparatory to rendering the blubber for oil. A Devonport entrepreneur organised a service car to transport sightseers to view the whales.

Strandings were public spectacles—especially when the victim was one of the great whales. When a 16-metre fin whale stranded on the beach at Hokitika in 1871, spectators paid more attention to the “distinguished visitor” than to the town’s annual regatta being held on the same day. Souvenir hunters took away chunks of skin or pieces of whalebone from the mouth. Refreshments were served on the whale’s back.

By the 1930s, Pākehā attitudes towards whales showed glimmerings of change. Whales started to be seen as sentient beings. (For Māori, they were always so.) When 90 pilot whales stranded at Ocean Beach, near the entrance to Whangarei Harbour, in 1930, a newspaper reported the event with a note of compassion hitherto absent from press coverage: “The huge creatures, as soon as they felt themselves against the rocks in the shallow breakers, began to bellow like stricken cattle. All except six of the fish were together on the beach, touching as if for sympathy.”

Rather than racing to stake a commercial claim on stranded whales, people began to try to rescue them. A pilot whale that stranded on rocks at Takapuna in 1939 was refloated by residents with the aid of ropes and clothesline props. Slowly, whale strandings came to be seen less as a curiosity and more as a calamity.

In the 1960s, Frank Robson pioneered techniques to rescue beached whales. A former fisherman, Robson became a dolphin trainer at Napier’s Marineland, but quit over disagreements about animal welfare and devoted the rest of his life to conservation of whales and dolphins in the wild. His experience in beach rescues and his understanding of stranding behaviour were fundamental in changing public perception of whales, including his belief that humans and whales can communicate telepathically.

By 1974, when international anti-whaling group Project Jonah began working in New Zealand, saving whales went mainstream. An important part of the awareness-raising effort was teaching people how to help stranded whales. Project Jonah began offering whale-saving workshops for the general public, and have continued to do so.

The need for such education became evident during a pilot whale stranding on Great Barrier Island in 1984, when concerned but misguided volunteers poured water down the blowholes of several whales, drowning them. Despite that setback, 67 of the 143 whales were refloated and successfully swam away. To ensure there was no repeat of bungled caregiving, whale rescue experts offered a training course for Great Barrier residents, and the following year, when an even larger pod of pilot whales stranded in Katherine Bay, 324 of the 450 beached whales were refloated—the largest rescue achieved so far.

As public interest in the welfare of whales surged, rescue techniques improved. Inflatable rescue pontoons were developed to support the animals while they were being refloated, and novel methods of luring them back to sea were trialled. It had long been known by whalers that adult whales will come to the aid of a stricken juvenile. So they would harpoon calves in a pod first, knowing that they could pick off the adults at their leisure. Flipping this behavioural trait around, rescuers tried positioning juveniles from a stranded herd offshore, in the hope that their calls would draw the adults in their direction. The ploy worked, and similar rescue techniques that make use of cetaceans’ social bonds are now standard practice.

More-traditional forms of Kiwi ingenuity were still important in the drama of a whale rescue. In 1991, when a pod of 30 pilot whales stranded near Shipwreck Bay, at the southern end of Ninety Mile Beach, refloating the 14 survivors was judged impossible because of the sea conditions. Instead, they were lifted by forestry machinery on to trucks lined with a mattress of hay and driven 50 kilometres to Doubtless Bay, on the opposite coast. The convoy even had a police escort to ensure there were no delays en route (apart from a couple of water stops to keep the animals hydrated). All the whales survived the journey and were successfully released.

With increased public sensitivity to whales, some aspects of managing a stranding have become more complicated. Tough decisions sometimes have to be made about whether to euthanise a whale. The default perception of many members of the public is that all stranded whales should be saved, but in cases where one may have sustained irreversible stress-induced organ damage, the more humane decision may be to end its suffering.

Public eagerness to refloat and release whales without delay can also cause problems. In 1993, efforts to refloat members of a pod of 120 pilot whales that stranded at Long Bay, on Auckland’s North Shore, ended in chaos when the beached whales were not given enough time to recover from their ordeal onshore. Pushed out to sea by well-meaning volunteers, many whales restranded immediately on nearby rocks, injuring themselves. The rest of the pod was held overnight and given a more organised send-off in the morning, when they could be escorted to sea by coastguard, surf club and police boats.

Pilot whales will continue to strand on our coastline. Human concern for cetaceans has never been higher, and anyone can receive training to become a “marine mammal medic”. So for whales that strand on our shores, the chances are good that many will live to tell the tale.